Gas chromatography/mass spectrometry (GC/MS) was used to investigate the main volatile components of the ethereal extract of roots of Securidaca longipedunculata Fres. (Polygalaceae), which are used by Guinea Bissau natives to obtain a drink with psychotropic effects and reputed to repel snakes and rodents due to a pungent smell. The roots were cleaned, cut, triturated, extracted with diethyl ether, and analyzed by GC/MS using a Finnigan Model 800 ion-trap detector and Carlo Erba Model 5160 gas chromatograph with an OV-17 column. Many components were detected, with main ones identified as benzoic acid derivatives (e.g., methyl 4-hydroxybenzoate, methyl 4-hydroxy-3-methoxybenzoate, methyl 2,6-dihydroxybenzoate, phenylmethyl 2-hydroxybenzoate) and other compounds like 4-(3-hydroxyprop-1-enyl)-2-methoxyphenol (coniferyl alcohol) and lumiflavin. In conclusion, different benzoic acid derivatives are the main volatile components, but their individual properties do not explain the repellent effects, which may arise from synergic effects of the mixture or uninvestigated minor components.